وَأَقَلُّ النِّفَاسِ لَا حَدَّ لَهُ، وَأَكْثَرُهُ أَرْبَعُونَ يَوْمًا، وَمَا زَادَ عَلَى ذَلِكَ فَهُوَ اسْتِحَاضَةٌ.
Meaning: There is no minimum duration for nifas; its maximum is forty days, and anything beyond that is istihadah.
Unlike hayd, nifas has no three-day minimum. A short episode after childbirth can still be nifas. Forty days is the Hanafi maximum.